| Sumario: | A minimal extension of the standard model (SM) with a single new mass scale and providing a complete and consistent picture of particle physics and cosmology up to the Planck scale is presented. We add to the SM three right-handed SM-singlet neutrinos, a new vectorlike color triplet fermion, and a complex SM-singlet scalar s that stabilizes the Higgs potential and whose vacuum expectation value at ~1011 GeV breaks lepton number and a Peccei-Quinn symmetry simultaneously. Primordial inflation is produced by a combination of s (nonminimally coupled to the scalar curvature) and the SM Higgs boson. Baryogenesis proceeds via thermal leptogenesis. At low energies, the model reduces to the SM, augmented by seesaw-generated neutrino masses, plus the axion, which solves the strong CP problem and accounts for the dark matter in the Universe. The model predicts a minimum value of the tensor-to-scalar ratio r?0.004, running of the scalar spectral index a?-7×10-4, the axion mass mA~100 µeV, and cosmic axion background radiation corresponding to an increase of the effective number of relativistic neutrinos of ~0.03. It can be probed decisively by the next generation of cosmic microwave background and axion dark matter experiments.
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